It is common in the farming industry to use conservation techniques such as strip tilling to reduce soil erosion. Strip tilling involves tilling one strip of soil while leaving the next strip, where no crops are to be planted, untilled. In addition to soil erosion the technique saves on labor and equipment.
As part of the effort to control labor and the costs of planting it is common practice to combine several operations such as tilling and applying fertilizer in one pass. It would be desirable to combine the steps of tilling, application of liquid fertilizer and planting into one pass but in the past this has been impractical because the liquid fertilizer would burn the seedlings.
Fertilizer burn occurs if concentrated liquid fertilizer gets on the seeds or seedlings. This will occur if liquid fertilizer, applied in a single stream, does not have time to spread out through the soil. Often fertilizer is applied in one pass and seeds are planted in a second pass several months later. Often the fertilizer application is done in the fall and seeds are planted in the spring. This technique tends to result in fertilizer ground water contamination and is being restricted in many states. Another technique is broad band application of the fertilizer on the surface of the soil but this technique tends to be wasteful as liquid fertilizer evaporates away very quickly if left exposed and again the technique tends to lead to over-application and ground water contamination. An additional consideration in tilling is to remove just enough of the old plant material to foster growth in the new seedling but to not remove too much old plant material as this would allow for excess erosion to get started.
Another consideration for many plants is to build a raised seed bed. In the spring, when planting occurs it is often wet. Too much moisture will cause seeds to rot in the ground and will stunt the growth of seedlings. For these reasons it is often desirable to build a slightly raised seed bed. This allows the ground immediately surrounding the seed to drain away any excess moisture while still retaining enough moisture for seed germination.
Prior art strip till equipment uses cultor wheels, followed by a conventional anhydrous knife, which is in turn followed by disc plows. This prior art arrangement has some limitations. The wavy coulter wheels are designed to chop up old vegetation but they tend to compact the deep soil as they lift the top layer. The prior art anhydrous knives can only loosen soil in a very narrow row perhaps 3 inches wide. The discs pulled behind tend to pull some soil back onto the row but again tend to pack the soil. A disadvantage of the use of discs is that they create a rut that contributes to erosion.
The invention relates generally to strip tillage and to the application of liquid fertilizer. A knife is disclosed that allows for liquid fertilizer to be applied under the seedbed in a broad band. This technique overcomes problems of delays in planting associated with waiting for liquid fertilizer to dissipate through the soil and problems with fertilizer losses associated with broad band surface applications. The technique also overcomes the serious problem of ground water contamination resulting from over application of fertilizer in the fall for spring plantings.
In applying anhydrous the material is a liquid under high pressure in the tank. When the anhydrous is applied, and pressure is released in turns to a gas. If the gas is not under the soil it will simply dissipate into the air. An advantage of the current invention is that it injects the anhydrous through a knife in a wide band that is typically 5-8 inches below the soil. Thus the anhydrous is contained and a minimum of loss occurs.
Old plant material is removed from the seedbed but not from the entire row. This way the old plant material provides some buffer against soil erosion.
The knife that allows for the application of fertilizer under the seedbed also tends to loosen the seedbed and to raise the seedbed. Rolling cultivators can be added to further raise the bed.
The invention can be mounted on a wheel-supported toolbar or on a toolbar mounted on a three-point hitch.